VFD output step-up transformer

[RRaghunath]

Recently, I have come across 3.3kV VFD output stepped up to 11kV supplying a 7MW motor. The step-up transformer is Y-D with floating neutral on star side.
I am used to Dyn connected captive transformers with the star point high resistance earthed. But, that is without VFD.
Is Y-D with floating neutral a requirement from VFD designer?? What could be the issues if we use Dyn with high resistance earthed neutral??
Thanks

 

[electricuwe]

The pulse pattern generation in VFDs relies on cancellation of certain harmonics in the current due to having no ground connection on the load side. Usually the load is a motor a no one would consider to ground the neutral of a motor with a star-connected stator.

 

[RRaghunath]

Thanks electricuwe. Appreciate your response.